In such a cine camera the perforated film must be transported intermittently, by the usual reciprocating-claw mechanism, past the exposure gate and at substantially constant speed past the recording head. An advantageous constant-speed feeder comprises a driven capstan and a pinch roller serving to clamp the film between itself and the capstan. Means for co-ordinating the two drives have been described in our prior application referred to above and in our copending application Ser. No. 669,085 filed Mar. 22, 1976 as a continuation-in-part thereof.
As further disclosed in that prior application and in the aforementioned continuation-in-part thereof, as well as in our copending applications Ser. Nos. 669,338 and 669,110 filed Mar. 22, 1976 as two other continuations-in-part of that prior application, the pinch roller and the capstan should be widely separated during the loading of the camera with a sound-film cassette in order to provide the necessary clearance for the insertion of an unsupported stretch of film therebetween; upon such insertion, and prior to the operation of a release button or trigger to start the film drive, the pinch roller and/or the capstan must be displaced to reduce their separation in order that a sound film can be engaged and transported thereby. Such displacement need not immediately clamp the film between the capstan and the pinch roller but may establish an intermediate or standby position from which the clamping position is reached upon operation of the trigger. In accordance with the disclosure of our two copending applications last referred to, the relative displacement of the pinch roller and the capstan from a retracted insertion position to at least a standby position is carried out either under the control of a sensor, detecting the presence of a sound-film cassette in a receiving chamber of the camera casing, or with the aid of a manually operable external actuating member on that casing, this actuating member being independent of the trigger and comprising for example a bar manipulable by the fingers of a user or a door or lid of the cassette-receiving chamber.